nystatin
Mycostatin, Nilstat, Nystat, Nystex, Pedi-Dri

Available forms
Available by prescription only
Cream: 100,000 units/g
Lozenges: 200,000 units
Ointment: 100,000 units/g
Powder: 100,000 units/g
Powder for suspension: 50-, 150-, 500-million units; 1-, 2-, 5-billion units
Suspension: 100,000 units/ml
Tablets: 500,000 units
Vaginal suppositories: 100,000 units

Indications and dosages
 GI infections. Adults: 500,000 to 1 million units as oral tablets, t.i.d.
 Oropharyngeal candidiasis. Adults and children: 400,000 to 600,000 units of oral suspension q.i.d. Or, 200,000 to 400,000 units (lozenges) four to five times daily for up to 14 days; allow to dissolve in mouth.
Infants: 200,000 units of oral suspension q.i.d.
Neonates and premature infants: 100,000 units of oral suspension q.i.d.
 Oropharyngeal candidiasis in HIV-infected patients. Adults: 500,000 to 1,000,000 units 3 to 5 times daily as oral suspension or tablets (dissolved in mouth). Or, oral lozenges may be used.
 Cutaneous or mucocutaneous candidal infections. Topical use: Apply to affected areas b.i.d. or t.i.d. until healing is complete (about 2 weeks).
Vaginal use: 100,000 units, as vaginal tablets, inserted high into vagina daily or b.i.d. for 14 days.
 For prevention of thrush in the neonate, 100,000- to 200,000-unit vaginal tablets daily for 3 to 6 weeks before delivery.
 Candidal diaper dermatitis. Infants: 100,000 units of oral suspension P.O. q.i.d. as an adjunct to topical nystatin therapy.

Pharmacodynamics
Antifungal action: Nystatin is both fungistatic and fungicidal. It binds to sterols in the fungal cell membrane, altering its permeability and allowing leakage of intracellular components. It acts against various yeasts and fungi, including Candida albicans.

Pharmacokinetics
Absorption: Not absorbed from GI tract or through intact skin or mucous membranes.
Distribution: No detectable amount is available for tissue distribution.
Metabolism: No detectable amount is systemically available for metabolism.
Excretion: Oral nystatin is excreted almost entirely unchanged in feces.

Contraindications and precautions
Contraindicated in patients hypersensitive to drug.

Interactions
Drug-herb. Brewer’s yeast: Reduces activity. Discourage use together.

Adverse reactions
GI: transient nausea, diarrhea (usually with large oral dosage), vomiting (with oral administration or vaginal tablets).
Skin: occasional contact dermatitis from preservatives in some forms (with topical administration or vaginal tablets).

Effects on lab test results
None reported.

Overdose and treatment
Overdose may result in nausea, vomiting, and diarrhea.
 Treatment is unnecessary because toxicity is negligible.

Special considerations
• Avoid contact between drug and hands; hypersensitivity is rare but can occur.
• For treatment of oral candidiasis, patient should have a clean mouth and should hold suspension in mouth for several minutes before swallowing. For infant thrush, medication should be swabbed on oral mucosa.
• Oral suspensions shouldn’t be mixed in food or beverages.
• May give immunosuppressed patient vaginal tablets (100,000 units) orally to provide prolonged drug contact with oral mucosa; or, use clotrimazole troche.
• For candidiasis of the feet, patient should dust powder on shoes and stockings as well as feet for maximal contact and effectiveness.
• Avoid occlusive dressings or ointment on moist covered body areas that favor yeast growth.
• To prevent maceration, use cream on intertriginous areas and powder on moist lesions.
• Clean affected skin gently before topical application; cool, moist compresses applied for 15 minutes between applications help soothe dry skin.
• Douches may be used by nonpregnant women for aesthetic reasons; they should use preparations that don’t contain antibacterials, which may alter flora and promote reinfection.
• Protect drug from light, air, and heat.
• Refrigerate vaginal tablets, oral suspension, and lozenges.
• Drug is ineffective in systemic fungal infection.
Breast-feeding patients
• Safety in breast-feeding women hasn’t been established.

Patient education
• Teach patient signs and symptoms of candidal infection. Inform patient about predisposing factors, such as use of antibiotics, hormonal contraceptives, and corticosteroids; diabetes; infected sexual partners; and tight-fitting pantyhose and undergarments.
• Teach good oral hygiene. Explain that overuse of mouthwash and poorly fitting dentures, especially in elderly patients, may alter flora and promote infection.
• Tell patient to continue using vaginal cream through menstruation; emphasize importance of washing applicator thoroughly after each use.
• Advise patient to change stockings and undergarments daily; teach good skin care.
• Teach patient how to administer the dosage form prescribed.
• Tell patient to continue drug for at least 48 hours after symptoms clear to prevent reinfection.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use